But promoted Norwich’s decent away record on their return to the top flight, one defeat in four, was enough to suggest they would fight back — and the response came on 19 minutes.

Left-back Martin Olsson was released down the wing to cross. Striker Dieumerci Mbokani karate knocked it home at the near post. His second goal in as many appearances.

Just as it seemed the early confidence had drained from the home side, they were back in front – Wijnaldum again the spearhead.

Sissoko flicked over an inviting cross and the former PSV Eindhoven star powered a header under John Ruddy, who might have got down quicker to save.

In on the act – Ayoze Perez also got among the goals:

(Image: Getty)

(Image: Action Images via Reuters)

Sissoko made it a hat-trick of assists after 33 minutes.

Jack Colback got in a good block on the edge of the area and the French midfielder carried the ball 50 yards. He slipped Perez into space and though the Spaniard's first shot was blocked by Olsson, he smashed his second effort home.

That should have signalled a period of calm, but the crazy, goal-laden start continued.

A minute later, Norwich were back in it. Another unchallenged cross from Olsson picked out Nathan Redmond unmarked on the right side of the box, and he volleyed home.

Had the Canaries scored first after the break, it could have been a different game.

Instead Mitrovic collected a through ball on his chest and volleyed home in the 64th minute to give United a cushion that was made more comfortable when Wijnaldum headed home Daryl Janmaat’s cross for his hat-trick.

The Dutch star, who won the Eredivisie title with PSV last season, took his personal tally to four on 84 minutes, blasting a deflected shot past Ruddy.